Centrifuges, for example, basket centrifuges, are commonly used to separate solid particulates from the liquid portion of a slurry and thereby form a cake of the solid particulates on the wall of the centrifuge. The centrifuges generally comprise a rotating perforated cylinder or basket. A filter cloth lines the interior of the cylinder. As the cylinder is rotated, a feed pipe is used to direct a flow of slurry onto the interior wall of the cylinder. The centrifugal force generated by the rotation of the cylinder separates the liquid portion of the slurry from the solid particulates, expelling the liquid from the cylinder and depositing the solid particulates on the filter cloth thereby forming a cake of solid particulates on the interior wall of the centrifuge.
The feed pipe, specifically the nozzle of the feed pipe, is generally spaced apart from the interior wall of the cylinder such that the cake may be deposited between the interior wall and the nozzle. However, if the flow rate or feed pressure of the slurry is low, the slurry exiting the nozzle may not reach the interior wall of the cylinder and, instead, may fall to the bottom of the cylinder causing the cake to be deposited on and build from the bottom of the cylinder. When the cake builds from the bottom of the cylinder, the filtering efficiency of the centrifuge is reduced. The cylinder may also become unbalanced which may result in damage to the centrifuge.
To prevent the slurry from falling to the bottom of the cylinder the feed pipe may be moved closer to the interior wall. However, when the feed pipe is moved closer to the interior wall of the cylinder, the nozzle of the feed pipe and/or the feed pipe may mechanically contact the cake as the thickness of the cake increases during operation of the centrifuge. Accordingly, the cakes formed may be thinner resulting in production inefficiencies. Further, moving the feed pipe closer to the interior wall of the cylinder may result in the feed pipe interfering with other components of the centrifuge.
Accordingly, a need exists for alternative centrifuges for forming cakes of solid particulates from a slurry.